On 18.12.2025 16:15, Grygorii Strashko wrote: > From: Grygorii Strashko <[email protected]> > > Extend coverage support on .init and lib code. > > To enable coverage support on .init code the gcc special > section should stay in memory after Xen boot when COVERAGE=y.
What is "the gcc special section" here, and ... > So, add hidden Kconfig option RELAX_INIT_CHECK "Relax strict check for > .init sections only in %.init.o files", which is selected when COVERAGE=y > and allows to bypass strict check for .init sections only in %.init.o > files. ... why / how would this mechanism get in the way? > --- a/xen/Rules.mk > +++ b/xen/Rules.mk > @@ -33,11 +33,15 @@ cov-cflags-y := > nocov-y := > noubsan-y := > > +# when coverage is enabled the gcc special section should stay in memory > +# after Xen boot Nit: Comment style (./CODING_STYLE applies to Makefile-s equally in this regard). > +ifneq ($(CONFIG_COVERAGE),y) > SPECIAL_DATA_SECTIONS := rodata $(foreach a,1 2 4 8 16, \ > $(foreach w,1 2 4, \ > rodata.str$(w).$(a)) > \ > rodata.cst$(a)) \ > $(foreach r,rel rel.ro,data.$(r).local) > +endif > > # The filename build.mk has precedence over Makefile > include $(firstword $(wildcard $(srcdir)/build.mk) $(srcdir)/Makefile) > @@ -146,10 +150,9 @@ endif > $(call > cc-option-add,cov-cflags-$(CONFIG_COVERAGE),CC,-fprofile-update=atomic) > > # Reset cov-cflags-y in cases where an objects has another one as > prerequisite > -$(nocov-y) $(filter %.init.o, $(obj-y) $(obj-bin-y) $(extra-y)): \ > - cov-cflags-y := > +$(nocov-y) $(extra-y): cov-cflags-y := > > -$(non-init-objects): _c_flags += $(cov-cflags-y) > +$(obj-y) $(obj-bin-y) $(extra-y) $(lib-y): _c_flags += $(cov-cflags-y) > > ifeq ($(CONFIG_UBSAN),y) > # Any -fno-sanitize= options need to come after any -fsanitize= options > @@ -259,8 +262,8 @@ $(obj)/%.o: $(src)/%.S FORCE > $(call if_changed_dep,cc_o_S) > > > -quiet_cmd_obj_init_o = INIT_O $@ > -define cmd_obj_init_o > +quiet_cmd_obj_init_check = INIT_C $@ > +define cmd_obj_init_check > $(OBJDUMP) -h $< | while read idx name sz rest; do \ > case "$$name" in \ > .*.local) ;; \ > @@ -269,12 +272,17 @@ define cmd_obj_init_o > echo "Error: size of $<:$$name is 0x$$sz" >&2; \ > exit $$(expr $$idx + 1);; \ > esac; \ > - done || exit $$?; \ > + done || exit $$? > +endef The " || exit $$?" isn't needed anymore when this is the last command? > +quiet_cmd_obj_init_objcopy = INIT_O $@ > +define cmd_obj_init_objcopy > $(OBJCOPY) $(foreach s,$(SPECIAL_DATA_SECTIONS),--rename-section > .$(s)=.init.$(s)) $< $@ What use is this step when $(SPECIAL_DATA_SECTIONS) isn't set at all? > endef > > $(filter %.init.o,$(obj-y) $(obj-bin-y) $(extra-y)): $(obj)/%.init.o: > $(obj)/%.o FORCE > - $(call if_changed,obj_init_o) > + $(if $(filter y,$(CONFIG_RELAX_INIT_CHECK)),,$(call > if_changed,obj_init_check)) > + $(call if_changed,obj_init_objcopy) Feels pretty fragile to do the modifications (as per above - if there were any in the first place) without first having checked that doing them is actually (going to be) okay. Furthermore - why RELAX_INIT_CHECK when you don't really "relax" it, but skip it altogether? Jan
